1. Field of Invention
This invention relates to the field of personal comfort devices, specifically, evaporative personal cooling devices that can be worn by humans or animals.
2. Prior Art
Throughout history, people have used various methods in attempts to keep themselves cool on hot days and in hot environments, especially when engaged in strenuous activities. Simple methods of personal cooling include wearing a moistened bandanna around one's neck, shading oneself with a hat or parasol, manually fanning oneself, using portable fans and/or misting devices, wetting or removing one's clothing, and changing into lighter clothing. All of these attempts have at least one of the following disadvantages:                The user must hold a device or take some action to derive a benefit (which is not only bothersome but may be tiring and self defeating, since such activity can generate more internal heat than it dissipates).        Removing clothing is often inappropriate or undesirable.        Changing into lighter clothing is often inconvenient or inappropriate.        Wetting the body and/or clothing can be uncomfortable, unaesthetic, or even embarrassing.        They provide only short-term relief.        They provide relatively ineffective cooling.        They are impossible or impractical to implement when wearing heavy or protective clothing or equipment.        They do not cover as large an area as needed.        
With the development of modern technologies, new ways have been found to produce a portable cooling effect, including:                Pumping cool gels or fluids through a vest or other garment        Creating portable refrigerators with chlorofluorocarbon coolants        Transferring coolness from a refrigerator or freezer to the body through liquids, gels, or solid materials        Using compressed gas to create a stream of cool air or vapor across the skin        Employing Peltier (thermoelectric) cells        
Still, each of these methods has serious drawbacks for the average user, due to cost, complexity, lack of portability, discomfort, difficulty of use, and/or lack of effectiveness. Most of these applications are ineffective because they require more energy than today's batteries can deliver beyond a brief period.
Because the evaporative cooling effect of water is simple and economical to harness, many personal evaporative cooling systems have been developed and refined over the years. U.S. Pat. Nos. 5,775,590 by Utter (Jul. 7, 1998) and 5,671,884 by Restive (Sep. 30, 1997) describe devices consisting of a portable water reservoir that, when pressurized by a user, propels water through a hose and out through a tiny nozzle, spraying the user with a fine water mist. By securing the device to the user's body with a belt or strap and by providing a clip that allows the user to direct the mist, these devices create a portable hands-free evaporative cooling effect. The disadvantages of this approach include: 1) the effect is very localized, 2) they wet the user's body and clothing, 3) they require the user to manually pressurize the bottle at intervals, 4) they require the user to move the nozzle to cool other areas of the body, and 5) because they do not use a fan, the cooling effect is minimal and inconsistent (a breeze is necessary for maximum effectiveness).
In an attempt to provide the needed moving air, there are a number of devices that allow the user to mist himself or herself while also employing a fan to move air across the moistened skin. U.S. Pat. No. 5,667,731 by Junket, et al. (Sep. 16, 1997) discloses a combination spray bottle and fan. It allows the user to spray himself with water while simultaneously directing the fan across the dampened skin. While this device makes up for the lack of moving air in the previously mentioned devices, it suffers from the remaining disadvantages already mentioned and additionally requires the user to hold the bottle and squeeze the trigger at intervals.
My U.S. Pat. No. 5,802,865 (Sep. 8, 1998) discloses a cooler that uses a fan to evaporate water from a powder-coated heat sink within the device and delivers the resulting coolness to the neck or forehead of the user without requiring the user to hold anything, do anything, or get wet. However, because this device is not flexible, it must be made to fit specific neck or head sizes and is not appropriate for other applications. The lack of flexibility also prevents this device from being used on a larger area of the body, and therefore does not cool the user nearly as much as would be desirable.
U.S. Pat. No. 6,371,388 by Utter, et. al (Apr. 16, 2002) discloses a device is that is strapped to the front of a user's body, and blows air mixed with a water mist up the front of the user's body. This approach has several disadvantages: 1) it wets the user's shirt, 2) because it blows over the user's shirt, it has little effect on cooling the user's torso, 3) it destroys the user's hairdo, 4) it requires the user to manually trigger the water spray, and 5) it is bulky, unattractive, and relatively expensive.
My U.S. Pat. No. 6,543,247 (Apr. 8, 2003) discloses a device that is strapped to the front or rear of a user's body and blows air mixed with a water mist up the front or back of a user's body under his or her shirt or blouse. This approach has the advantages of not wetting the user's clothes and, because the air/water stream is moving directly against the skin, produces a reasonable cooling effect over a larger area than most evaporative cooling devices. But this technique still has certain disadvantages, such as: 1) it does not cool the torso as much as desired, 2) it wets the user's skin, 3) inexpensive embodiments require the user to trigger the water spray manually, 4) it cannot cool the back of a hiker wearing a backpack, and 5) it cannot cool users who are wearing motorcycle leathers, protective suits, or tightly fitting clothing.
U.S. Pat. No. 6,257,011 by Siman-Tov, et al. (Jul. 10, 2001) reveals a portable lightweight cooling garment having a channeled sheet that absorbs sweat and/or evaporative liquid, a layer of highly conductive fibers adjacent to the channeled sheet and a device for moving air through the sheet. U.S. Pat. No. 6,134,714 by Uglene (Oct. 24, 2000) discloses a personal cooling garment with inner and outer layers defining a confined space for containing liquid that can evaporate to create a cooling effect. The drawback of both approaches is that they do not increase the surface area beyond what is provided by the user's skin, and therefore can only make the evaporative cooling effect somewhat more consistent, but not more cooling than perspiring on a breezy day.
U.S. Pat. No. 5,755,110 by Silvas (May 26, 1998) describes a cooling vest having a plurality of elongated pocket partitions containing beads of polyacrylamide. These absorb liquid to form a gel that may be chilled or frozen to provide a cooling effect on the upper torso of a human wearer. The problem in all such approaches is that the cooling effect is neither as strong as desired nor as long-lasting as users would wish.